It is recommended for 93 LS4 that ATF Type T - II, are to be used for the transmission fluid. I am thinking of changing the fluid without taking the pan off to replace the fluid (drain & fill). The Service manual says only need to refill 2 quarts after the drain.

I have done the trans fluid/filter replaced by a trans specialist while back. The shop is no longer in business but at the time, I think they have told me they are replacing the fluid with Dextron III, but not sure.

Question I have are:
- Is is possible to put the Dextron III to 93 LS4 trans?
- If so, not knowing exactly what type of fluid is in the trans, can I go ahead and use ATF Type T?
- If not, is there a way to know what type of trans fluid is currently in my trans?

Any input on the subject would be appreciated.

 

Only use Toyota Type IV fluid. You can just drain refill occasionally 2 qts at a time with the correct fluid and you should be ok. You should be able to get it through any Toyota/Lexus dealer. Carquest also sells it in my area.

 

no, dexron or similar won't work.

Toyota T-II was superseded by T-IV, available at any local toyota/lexus dealership. (aka Mobil 3309)

 

So type T-IV is same as Mobil 3309 ie. identical?

 

yes, absolutely identical, made on the same filling lines at Exxon Mobil, and also available as a Mazda, Saab, and several other brands

 

If the Dextron would not work on the Lexus trans, is it safe to assume the trans fluid in the trans is the Type-T?

Then the question becomes, can I just empty out 2 Quarts of Type-T II and refill with Type-T IV?

 

Dexron was used at a certain point but type iv has more advanced friction modifiers and is now universally recommended. In other words, it is more advanced and is better for the transmission. Dexron actually will work and not damage the transmission but it is not the ideal fluid. Dexron III and type IV are very similar. The fluid base is the same. The difference is the friction modifiers. Lexus even used Dexron at one point. Oh, and it's Dexron not Dextron. I left that T in there myself for I don't know how long... lol

In my opinion, I would just do the drain and refill using type iv unless you feel like dropping the pan again. Yamae spoke on this in some thread.

 

Let me go back to my original question.

I do not know weather there is Dexron or Type T is in my trans. Is there a way to tell which type is in my trans?

Without knowing what is in the trans, can I drain using drain plug and add either Dexron or Type-T in there. I may be mixing one with the other. See the issue I have?

Weather I use Dexron or type-T to add, whatever the last roman number will always be the latest new and improved and always superseeds the previous roman numeral version, is my understanding,

For the power steering, it is indicated on the power steering cap, to use Dexron trans fluid.

 

The two are not incompatible. Ideally you want all of the fluid to be type iv. But I would not flush the system as to avoid shocking the transmission. Just do the drain and refill using type iv. Repeat every 5k miles for about 25k miles if you are worried about it. Otherwise, just do the drain and refill every 30k. Or drop the pan again and use the correct fluid. You are not damaging your transmission with Dexron in there. It just won't shift as nice vs having type iv. I like Cowboys advice of doing a quart every few months.

 

just change 1 or 2 quarts maximum at a time, and slowly transition over to full T-IV, do the 1 or 2 quart drain and fill every few months. T-IV will mix with anything that is in your transmission.

 

Lavrishevo, LScowboy,

Thank you for your tip. I will follow your instructions. However, if something goes wrong with the trans, I am coming after you guys

I will do some more research on the subject before I move forward as this is not the most urgent issue with the car at this point and I am dealing with an automatic transmission here. I have be absolutely sure of what I am doing. And when I find anything new on the topic, I will post it back in this forum.

Thanks again.

 

that's why you go slow and careful, just a couple of quarts at a time, every 4 months or so.

Ignore the people who think you need to "flush" your tranny, they will end up costing you a new one!

and besides, mathematically, if you change out even a single quart, enough times, over time, the system is flushed!!

 

Thanks mate.

Mobil 3309 is available on every local parts store shelf but Type T-IV not in town - not even local Toyota dealer as far as I can tell.

 

you can even find it at the Volvo dealership! - here is T-IV in a Mazda bottle


[/QUOTE]